BREEDING TUBERCLES IN FISHES COLLETTE 577 



that they are close to spawning condition. Several of the males are 

 extremely darkly pigmented. Crawford (1956) thus describes sexual 

 dimorphism in P. n. nigrojasciata: The males are larger and darker 

 than females; the vertical bars of the males tend to be more discrete 

 and less confluent; enlarged ctenoid scales are present along the 

 midventral line on the males' bellies; and the genital papillae in the 

 females are long, conical, and clearly villiform. 



No tubercles are present on specimens of P. sclera in three Okla- 

 homa-Texas collections taken in March and April. The testes and 

 ovaries of all these specimens are greatly enlarged. The vertical 

 banding present in the females becomes completely obscured by the 

 dark pigment in breeding males. The fins, belly, and breast are 

 almost black in these males. Males have enlarged scales along the 

 midventral line of their bellies. 



There are no tubercles on the two males of the recently described 

 P. lenticula collected in the spring (CU 43592, Alabama drainage. May 

 9, 96 mm., holotype; CU 43594, Alabama drainage. May 17, 86 mm., 

 paratyjie). There is little sexual dimorphism in color pattern (Rich- 

 ards and Knapp, 1963). 



Subgenus Swainia Jordan and Everniann 



There are four species in this subgenus : nasuta (Bailey) , oxyrhyncha 

 (Hubbs and Raney), phoxocephala (Nelson), and squamata (Gilbert 

 and Swain). I have examined 15 collections of P. phoxocephala 

 taken from mid-March to September (UMMZ, USNM, KU), a male 

 of oxyrhyncha taken on June 25 (UMAIZ 118422, holotype), a male 

 of squamata taken on May 25 (UMMZ 177816), and 5 males of nasuta 

 taken on April 26 (CU 41971), and have found no tubercles. Traut- 

 man (1957, p. 543) reported that breeding males of P. phoxocephala 

 are more intensely colored than females and have orange bands on the 

 first dorsal fin. 



Subgenus Percina Haldeman 



There are two species in this subgenus: caprodes (Rafinesque), with 

 several subspecies, and rex (Jordan and Evermann). Tubercles are 

 present on the ventral scale rows of the males of both species. Tu- 

 bercles seem to be better developed and present for a longer period in 

 southern populations, Percina caprodes carbonaria (Baird and Girard), 

 than in northern ones. Both species have low rounded tubercles 

 on the posterior part of the scales. The tubercles are usually not 

 prominent, so that magnification and drying are necessary to trace 

 their extent. No fin tubercles were found, and the females lack 

 tubercles altogether. 



